1. Field of the Invention
The present invention relates to an apparatus and method for chemically treating thin materials.
2. Description of the Prior Art
In the electronics industry, the art has developed progressively thinner printed circuit boards to the extent that the rigid or semi-rigid printed boards have become increasingly thinner and approach or become more of a flexible film. The processing of such "boards", which can more precisely resemble films, presents new concerns in the handling of these articles, as the thin materials have a tendency to buckle and cause jamming of the treatment or processing apparatus. Attempts to deal with this generation of printed boards have relied on providing additional supports to retain the film in place as it travels through a processing apparatus or treatment center. For example, additional bands or wires running the length of an apparatus have been employed in the transport areas for support to prevent jamming of the films against or under the drive rods which move the articles through the machine. However, the presence of stationary wires running the length of the apparatus, often tend to prevent the etchant spray or other treatment fluid from reaching the board area covered by the wire. This results in an undesirable masking or shadow effect, and does not provide a uniform etch or other treatment. Attempts to deal with this problem have largely been to use an arrangement of several fixedly disposed bands at staggered positions along the transport means and as in U.S. Pat. No. 4,781,205.